The present invention generally relates to fuel-fired heating appliances and, in representatively illustrated embodiments thereof, more particularly provides a fuel-fired instantaneous water heater having a special construction that permits it to utilize a low temperature plastic vent structure.
Fuel-fired instantaneous type water heaters have combustion systems designed to heat water as it is being supplied to one or more plumbing fixtures to which it is operatively connected as opposed to heating a stored quantity of water for subsequent delivery to such fixtures. Due to their high flue exhaust temperatures, conventional power vented instantaneous fuel fired water heaters installed indoors have typically had to utilize category III high grade stainless steel (AL-29-4C) vent systems and materials. These necessary stainless steel vent systems, which are usually specified and/or supplied in kit form with the water heater, are expensive, difficult to install, non-interchangeable across various manufacturers, and difficult to source through retail and wholesale distribution centers.
It would be highly desirable to provide a fuel-fired instantaneous type water heater which could utilize a lower cost plastic vent system instead of the conventionally required stainless steel vent system. It is to this goal that the present invention is primarily directed.